Survival by Hispanic ethnicity among patients with cancer participating in SWOG clinical trials

Racial disparities in cancer outcomes have been described. To the authors' knowledge, it remains unclear whether patients of Hispanic ethnicity have better or worse survival outcomes. In the current study, the authors evaluated whether Hispanic participants in SWOG clinical trials had different survival outcomes compared with non-Hispanics.

Adult patients registered in SWOG phase 2/3 clinical trials between 1986 and 2012 were analyzed. Studies of similar histology and stage of disease were combined. Within each analysis, Kaplan-Meier survival curves were generated to examine differences in outcome by ethnicity. Multivariate Cox regression was used to estimate the association between ethnicity and survival outcomes, controlling for major disease-specific prognostic factors and demographic variables plus area-level income and education to account for socioeconomic status.

A total of 29,338 patients registered to 38 trials were included; 5% of these patients were Hispanic. Hispanic patients were more likely to be younger and from areas of lower income and education (all P<.05). No differences in survival were observed across tumor types except in the patients with advanced stage prostate cancer, in whom the authors observed an association between Hispanic ethnicity and worse overall survival (hazard ratio [HR], 1.40; P = .006), progression-free survival (HR, 1.36; P = .007), and cancer-specific survival (HR, 1.42; P = .013). After adjusting for multiple comparisons, no differences in outcomes were noted.

Hispanic patients participating in SWOG trials who received uniform treatment and follow-up were found to have similar survival outcomes compared with non-Hispanic patients, with the single exception of those patients with advanced stage prostate cancer. The results of the current study demonstrate that Hispanic patients receiving uniform treatment and follow-up have similar outcomes compared with non-Hispanics. Cancer 2018;124:1760-9. © 2018 American Cancer Society.